Tree planting: Is the performance gap growing and not the trees?

THE recognition of trees and the benefits they provide, and the increased focus on planting more trees is to be welcomed and many would say long overdue, but there must be an outcome which can be summarised as Trees: From Nursery to Independence in the Landscape. This is the title of the British Standard 8545 published in 2014. Tree planting by numbers and percentages has a value, but this value is limited unless there is an accompanying vision and a means of assessing the success of tree-planting programmes. 

It would also appear there is a growing gap between the aspirations associated with tree planting and the reality on the ground. 

READ MORE: HSE launch probe after tree felled WRONG way in Crewe

The photographs accompanying this article offer an example of a site in East Sussex where a litany of poor practice is apparent. There is, for everyone to see, poor-quality nursery stock, poor planting, non-existent maintenance and inevitable decline and death and the trees have only been in the ground for one growing season at most. It would be easy to examine the planting in detail and once again reel off the things that have been done badly. The list will be familiar: inappropriate species choice, lack of head pruning of nursery stock, made-up root balls from the nursery, imported trees, planting too deep, inappropriate staking and underground support, failure to mulch where appropriate and so on and so forth.

But what would be the point? Surely the discussion around these failures and others are well versed and known factors within our industry. BS 8545: Trees: From Nursery to Independence in the Landscape was published in 2014 and all the factors apparent in the landscaping scheme referred to above were addressed. It was not a perfect document and is probably in need of updating now, but the main points were covered, and best practice recommended. 

Trees in Towns II, published in 2008, suggested over 25 per cent of newly planted trees in the public sector fail and consequently never deliver the benefits to society intended.

There has been little or no published data since this report which analyses how successful tree-planting programmes are and what benefits and public goods are delivered. Observation would indicate that planting success has not improved since the report was published. I can offer many examples including the scheme illustrated in the accompanying photographs, of where tree planting, carried out with the best of intentions, has failed to deliver ‘independence in the landscape’ and consequently the public goods and benefits associated with trees have been lost. The ‘Big Tree Plant’ was a government-sponsored campaign in England in 2010 to promote the planting of one million trees in neighbourhoods where people live, work and play. Tree planting was financed through government grants with proposals for funding submitted by public authorities, NGOs and community groups. The scheme was considered a success and the numbers to be planted achieved.

Exposed root ball made up, poor graft union. (Image: EA)

The Boris Johnson administration at the Greater London Authority sponsored the planting of 10,000 urban trees during each of his two terms of office. Again, planting was financed by grants with public authorities bidding for funding and again the numerical targets were achieved. Many other governments’, both central and local, planting initiatives have been completed in addition to the numerous initiatives led by NGOs and others. All have been well intentioned, but none, to my knowledge, have been subjected to long-term audit to establish whether the initiatives delivered the benefits and public goods intended.

The questions of auditing and accountability remain discussion points for another day, but the gap between aspirational tree planting to achieve the many benefits trees offer and delivery on the ground is getting wider.

The information in the public domain about tree planting and management is extensive and certainly beyond the scope of this article to outline in full. The number of research papers from the UK and beyond is staggering, almost beyond reading because of the volume involved.

The two TDAG documents, Trees in the Townscape and Trees in the Hard Landscape, offer extensive guidance as to best practice, coupled with numerous case studies. BS 8545 Trees: From Nursery to Independence in the Landscape, referred to above, offers stage-by-stage advice. There is need for some updating, but the information contained in it is as good today as it was on publication. The TDAG Guide to Tree Species Selection, written by Dr Andrew Hirons and Dr Henrik Sjoman, is arguably the best of its kind, offering detailed information about individual tree species and their suitability for planting in the urban environment. There have, in recent years (supported by the Arboricultural Association, the London Tree Officers Association, Barcham Trees and many others), been many presentations at conferences and seminars in the UK from world-renowned researchers such as Dr Ed Gilman and Dr Gary Watson, whose book,

The Practical Science of Planting Trees, published in 2013, remains one of the most comprehensive sources of information available. The above references are just the tip of the iceberg, so the reasons for the identified performance gap are not the availability of information and guidance.

Lack of mulch, grass competition, poor head pruning. (Image: EA)

Yet it is hard to avoid hearing the calls for more and more research. As always, more information is useful and new knowledge to be welcomed but – and this is a big but – what is the point if research and best practice bounces around in rarified circles of adherents and never finds its way down to implementation at the point of planting into the landscape?

During the many discussions had by the drafting panel of BS 8545, Tony Kirkham commented: “It is really easy to photograph badly planted trees, but really difficult to photograph well planted and thriving young trees.”

I would suggest that wherever you are reading this article you will not have to walk more than 1,000 metres to find examples of young trees poorly planted or poorly maintained that have absolutely no chance of delivering longevity, benefits or public goods into the future. Please accept the challenge. 

Discussions of the performance gap at recent TDAG meetings outlined the following:
• There is a lack of vision surrounding tree planting. While numbers (volume) and percentages (canopy cover) are used as criteria to inform tree-planting programmes, there is rarely any accompanying long-term vision. The question of what is to be achieved by planting trees is rarely addressed in terms of the desired benefits or over what period those benefits are to be achieved. The 
success of planting schemes is rarely assessed. The question as to whether the objectives of planting were achieved is rarely answered.

Poor crown structure. (Image: EA)
• It was generally agreed that practitioners, those who specify, procure, plant or manage young trees, have little or no understanding of the numerous nursery production systems and how best practice of those systems influences not only the procurement of high-quality young trees, but the likelihood of eventual success in the landscape post-planting.
• It was also agreed that there is an inadequacy in the writing and enforcement of specifications. There is rarely any vision statement within a planting specification and rarely a full and clear description of the desired outcome. Performance towards this desired outcome is rarely measured, even if there is an attempt at expressing one.
• Even with all the information available through research and best practice documents, planting is still often poorly executed with basic mistakes being made.
• Post-planting management is universally recognised as being poor. Watering regimes are still mainly addressed in terms of amount/frequency or both and not on the actual need of any newly planted group or population of trees. There is a general failure to recognise that the nursery tree is not the finished article but a stage in a growing and development process which needs to be considered for several years after planting.

Hence the title of BS 8545: Trees: From Nursery to Independence in the Landscape.

The challenge then is to convert the already copious amounts of research and best practice guidance into action on the ground where it really matters. Continually reading and researching without implementation becomes a virtuous but meaningless exercise in self-congratulatory naval gazing. It would do us all good to look in the mirror.

It might be worth noting that the well-known Barcham Seminar Series is to be resumed in the very near future with events held not only at Barcham Trees Nursery but at venues around the country. Watch this space for further details or contact me at keith@barchamtrees.co.uk if you would like to discuss.